| 摘要 |
PROBLEM TO BE SOLVED: To realize the highly accurate wavelength-controllability of a semiconductor laser module, by providing in a package a plurality of semiconductor lasers for emitting respectively laser beams, and by selecting one of them to set the selected one to a drive-able state. SOLUTION: A semiconductor laser module 1 is so configured that it has a plurality of semiconductor lasers 35 and when the reduction of the output power of the one used semiconductor laser 35 occurs the other semiconductor lasers 35 are changed over into each other successively to make usable one of them. Further, the respective semiconductor lasers 35 are so configured as to have different oscillation wavelengths from each other. Also, the used environmental temperatures of the respective semiconductor lasers 35 of the semiconductor laser module 1 are controlled by a single electronic cooling element 33. When using each semiconductor 35, a user controls its used environmental temperature by the electronic cooling element 33 while referring to the data for showing the relation of its oscillation wavelength to its temperature, and the user changes over the lasers 35 into each other to use one of them. Thereby, the semiconductor laser module 1 which oscillates always at a constant wavelength can be constructed. |
